Nitrogen → tert-Butyl 7-(4-(benzyloxy)-2-oxopyridin-1(2H)-yl)-5-methyl-3,4-dihydro-1H-pyrido[4,3-b]indole-2(5H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

tert-Butyl 7-bromo-5-methyl-3,4-dihydro-1H-pyrido[4,3-b]indole-2(5H)-carboxylate (7.0 g, 19 mmol), 4-benzyloxypyridone (3.85 g, 19.2 mmol), K2CO3 (2.91 g, 21.1 mmol) and 8-hydroxyquinoline (418 mg, 2.88 mmol) were suspended in DMSO (50 mL) and the air removed under vacuum for 15 min. The system was then flushed with N2. This process was repeated and then copper iodide (547 mg, 2.88 mmol) was added. The evacuation/N2 flushing process was repeated twice more, and the reaction mixture was heated to 100-120° C. for 18 h. The mixture was cooled, partitioned between EtOAc and sat. NH4Cl and the organic phase removed, dried over Na2SO4, filtered and concentrated to dryness. Purification by flash column chromatography (silica gel, CH2Cl2/MeOH, 100:0 to 98:2 to 95:5 to 92:8 then 90:10) gave the title compound (4.71 g, 51%) as a yellow solid: 1H NMR (300 MHz, CDCl3) δ 7.50 (d, J=8.2 Hz, 1H), 7.43-7.35 (m, 5H), 7.32-7.29 (m, 2H), 7.01 (d, J=7.9 Hz, 1H), 6.10-6.03 (m, 2H), 5.06 (s, 2H), 4.64 (s, 2H), 3.89 (br t, 2H), 3.63 (s, 3H), 2.82 (br t, 2H), 1.50 (s, 9H).

Provenance & Evidence